1. Field of the Invention
The present invention relates to producing a wrought material with one or more enhanced mechanical properties. More particularly, the invention relates to producing a metal alloy wrought material, having micrometer sized grain structures for enhancing one or more mechanical properties such as strength and/or elongation.
2. Related Technology
Many metals, such as for example, Magnesium (Mg) and Aluminum (Al), represent light commercial metals for various structural applications, Mg being the lighter of the two. However, high impact resistant and formability applications require materials with sufficient strength and ductility to absorb the energy generated during an impact or forming process. This requirement limits the use of conventional Mg and Al alloys for such applications. For example, conventional Mg alloys have low yield strengths of about 130-180 MPa, have poor formability and have poor crack tolerance. These properties make conventional Mg alloys unsuitable for many applications because the alloy is more likely to crack after only moderate deformation.
The alloying elements that improve corrosion resistance and castability of various metals, such as Al additions to the Mg base, unfortunately introduce eutectic intermetallic phases, which envelope the primary grains in a coarse and brittle morphology in the commercial alloys. Furthermore, it is difficult to attain efficient age hardening by fine precipitates within the grains, as exemplified by the case of inefficient Al additions to Mg. Elements that promote age hardening in Mg, such as rare earth metals, are costly, detrimental to castability and ineffective in resisting corrosion. As a consequence of these barriers, increases in strength have been marginal, at best, and decade-old metal alloys, such as Magnesium based AZ31 and AZ91D, still dominate the tonnage of commercial sheet and casting markets, even though AZ31 lacks strength and AZ91D lacks ductility for many sheet markets.
Accordingly, there is a need for an apparatus and process that can be carried out in a rapid and automated manner so as to change alloy composition and grain structure, thereby allowing such processed alloys to be subsequently worked into impact resistant and/or formable wrought forms with sufficiently high strength and ductility.